Problem: Solve for $p$ : $29 = p + 4$
Explanation: Subtract $4$ from both sides: $ \begin{eqnarray} \\ \hphantom{29 {- 4}} &\hphantom{=}& \hphantom{p} \\ 29 &=& p + 4 \\ \\ {-4} && {-4} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ 29 {- 4} &=& p \\ \end{eqnarray} $ Simplify. $ p = 25$